Mbed OS Reference | SlicingBlockDevice.h Source File

 /* mbed Microcontroller Library
  * Copyright (c) 2017-2020 ARM Limited
  * SPDX-License-Identifier: Apache-2.0
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 /** \addtogroup storage */
 /** @{*/
 
 #ifndef MBED_SLICING_BLOCK_DEVICE_H
 #define MBED_SLICING_BLOCK_DEVICE_H
 
 #include "BlockDevice.h"
 #include "platform/mbed_assert.h"
 
 namespace mbed {
 
 /** Block device for mapping to a slice of another block device
  */
 class SlicingBlockDevice : public BlockDevice {
 public:
     /** Lifetime of the memory block device
      *
      *  @param bd       Block device to back the SlicingBlockDevice
      *  @param start    Start block address to map to block 0, negative addresses
      *                  are calculated from the end of the underlying block device
      *  @param end      End block address to mark the end of the block device,
      *                  this block is not mapped, negative addresses are
      *                  calculated from the end of the underlying block device.
      *                  The default stops at end of the underlying block device.
      */
     SlicingBlockDevice(BlockDevice *bd, bd_addr_t start, bd_addr_t end = 0);
 
     /** Lifetime of a block device
      */
     virtual ~SlicingBlockDevice() {};
 
     /** Initialize a block device
      *
      *  @return         0 on success or a negative error code on failure
      */
     virtual int init();
 
     /** Deinitialize a block device
      *
      *  @return         0 on success or a negative error code on failure
      */
     virtual int deinit();
 
     /** Ensure data on storage is in sync with the driver
      *
      *  @return         0 on success or a negative error code on failure
      */
     virtual int sync();
 
     /** Read blocks from a block device
      *
      *  @param buffer   Buffer to read blocks into
      *  @param addr     Address of block to begin reading from
      *  @param size     Size to read in bytes, must be a multiple of read block size
      *  @return         0 on success or a negative error code on failure
      */
     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
 
     /** Program blocks to a block device
      *
      *  The blocks must have been erased prior to being programmed
      *
      *  @param buffer   Buffer of data to write to blocks
      *  @param addr     Address of block to begin writing to
      *  @param size     Size to write in bytes, must be a multiple of program block size
      *  @return         0 on success or a negative error code on failure
      */
     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
 
     /** Erase blocks on a block device
      *
      *  The state of an erased block is undefined until it has been programmed,
      *  unless get_erase_value returns a non-negative byte value
      *
      *  @param addr     Address of block to begin erasing
      *  @param size     Size to erase in bytes, must be a multiple of erase block size
      *  @return         0 on success or a negative error code on failure
      */
     virtual int erase(bd_addr_t addr, bd_size_t size);
 
     /** Get the size of a readable block
      *
      *  @return         Size of a readable block in bytes
      */
     virtual bd_size_t get_read_size() const;
 
     /** Get the size of a programmable block
      *
      *  @return         Size of a programmable block in bytes
      *  @note Must be a multiple of the read size
      */
     virtual bd_size_t get_program_size() const;
 
     /** Get the size of an erasable block
      *
      *  @return         Size of an erasable block in bytes
      *  @note Must be a multiple of the program size
      */
     virtual bd_size_t get_erase_size() const;
 
     /** Get the size of an erasable block given address
      *
      *  @param addr     Address within the erasable block
      *  @return         Size of an erasable block in bytes
      *  @note Must be a multiple of the program size
      */
     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
 
     /** Get the value of storage when erased
      *
      *  If get_erase_value returns a non-negative byte value, the underlying
      *  storage is set to that value when erased, and storage containing
      *  that value can be programmed without another erase.
      *
      *  @return         The value of storage when erased, or -1 if you can't
      *                  rely on the value of erased storage
      */
     virtual int get_erase_value() const;
 
     /** Get the total size of the underlying device
      *
      *  @return         Size of the underlying device in bytes
      */
     virtual bd_size_t size() const;
 
     /** Get the BlockDevice class type.
      *
      *  @return         A string represent the BlockDevice class type.
      */
     virtual const char *get_type() const;
 
     /** Convenience function for checking block program validity
      *
      *  @param addr     Address of block to begin writing to
      *  @param size     Size to write in bytes
      *  @return         True if program is valid for underlying block device
      */
     virtual bool is_valid_program(bd_addr_t addr, bd_size_t size) const;
 
     /** Convenience function for checking block read validity
      *
      *  @param addr     Address of block to begin reading from
      *  @param size     Size to read in bytes
      *  @return         True if read is valid for underlying block device
      */
     virtual bool is_valid_read(bd_addr_t addr, bd_size_t size) const;
 
     /** Convenience function for checking block erase validity
      *
      *  @param addr     Address of block to begin erasing
      *  @param size     Size to erase in bytes
      *  @return         True if erase is valid for underlying block device
      */
     virtual bool is_valid_erase(bd_addr_t addr, bd_size_t size) const;
 
 
 protected:
     BlockDevice *_bd;
     bool _start_from_end;
     bd_size_t _start;
     bool _stop_from_end;
     bd_size_t _stop;
 };
 
 } // namespace mbed
 
 // Added "using" for backwards compatibility
 #ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
 using mbed::SlicingBlockDevice;
 #endif
 
 #endif
 
 /** @}*/
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